Is it reliable that Orangethroats have an all-blue anal fin without any red or orange spot?
And that Rainbows lack skimpy horizontal rows of dark spots on the upper sides not far behind the gills?
I've got some darters from Union Co., Illinois, that seem to be Rainbows, as the body depth is greatest below the 1st dorsal fin rather than in front of it, and they have large red/orange areas on the partly blue anal fin, so those traits are good for a Rainbow.
But they do have a few small dark flecks in more or less horizontal array, on the upper part of the forward part of the body, which is supposed to be an Orangethroat trait. I suspect that I shouldn't let these bother me, as the other things seem to say "Rainbow".